1. Field of the Invention
The invention concerns an atomizer for dispensing liquids for medical purposes, for example pharmaceutical active substance formulations, from at least one container for the liquid, which can be fitted into the atomizer (cartridge), as well as a cartridge and a system comprising an atomizer and a cartridge which can be fitted therein.
2. Description of the Prior Art
The known atomizers include as essential units a cartridge holder which is arranged in the housing, a mouthpiece which is provided on the housing and in which an atomization device is arranged, and a connecting tube system which connects the atomization device and the cartridge holder, wherein the atomization device has at least one nozzle body and the connecting tube system has at least one passage with a hollow plunger mounted displaceably therein, wherein the hollow plunger includes a valve body.
The hollow plungers which are inserted in the atomizers include a valve body. Upon a downward movement of the hollow plunger, in an open position, the valve body permits an intake flow of the formulation or formulations which are already mixed, into the portion of the passage which is downstream of the hollow plunger in the flow direction. Upon an upward movement of the hollow plunger the valve body closes the hollow plunger and, upon further upward movement, the formulation or the mixture disposed downstream of the hollow plunger in the flow direction is compressed to the desired pressure.
Atomizers of that kind are used for the application of liquid drug formulations which are effective by inhalation, in which case the liquid formulations must satisfy high quality standards. In order to achieve a good distribution of the active substances in the lung, application of a liquid formulation which does not involve the use of propellant gases, by means of inhalers or atomizers which are suitable for that purpose, presents itself as an option. Particularly suitable atomizers are those which can nebulize a small amount of a liquid formulation in the therapeutically necessary dosage into a therapeutically-inhalatively suitable aerosol, within a few seconds. In that respect the nebulization duration should be optimized in respect of time in order to guarantee optimum lung deposition. In accordance with the present invention, those nebulizers are preferred, in which an amount of less than 100 microliters, preferably less than 50 microliters, quite preferably less than 20 microliters of active substance solution are already atomized with one stroke or a few strokes to afford an aerosol with an average particle size of less than 20 micrometers, preferably less than 10 micrometers.
Such a device for propellant gas-free administration of a dosed amount of a liquid drug for inhalation use is described in detail for example in international patent application WO 91/14468 ‘Atomizing Device and Methods’ and also in WO 97/12687. In such an atomizer a drug solution is converted by means of high pressure of up to 500 bars into a lung-treating aerosol.
In the known atomizers the active substance formulations are stored in the form of solutions in a reservoir. In that case it is necessary for those solutions used to enjoy adequate storage stability and at the same time to be such that they can be applied directly in accordance with the medical purpose as far as possible without further manipulation. In addition, they should not have any constituents that can interact with the atomizer, so that neither the atomizer, nor the solution, nor the aerosol produced, suffer damage.
Nebulization of the solution is effected by using a special nozzle as is described for example in WO 94/07607 or WO 99/16530.
A further development in the construction of the preferred inhaler is also disclosed in WO 97/12687.
By virtue of its cylinder-like shape and its easily manageable size of less than 9 to 15 cm in length and 2 to 4 cm in width the known atomizers can be carried around by the patient at any time. The atomizer sprays a defined volume of the drug formulation using high pressures through small nozzles so that inhalable aerosols are produced.
EP 0 918 570 describes an atomizer for nasal sprays which as core components includes a spring-operated plunger and a nozzle device. It is possible to insert between the plunger and the nozzle a container which at its bottom has a ram and at its head side is closed by way of a seal. That seal of the container is opened prior to the first use by moving the external nozzle which is integrated in the atomizer through the seal.
The described atomizers, however, are primarily suited for the delivery of stable solution formulations, that is to say, for formulation constituents that can be stably mixed with each other and that can be stored over a prolonged period of time. Thus it is a prerequisite for example in the case of combination preparations which contain at least two active substances that the active substances to be administered are for example stable at the same pH-value in the same solvent.
In addition various principles of devices for administering medicaments are known from the state of the art, which are stored separately prior to their administration but which are then available to the patient as a mixture.
WO2004/011068 discloses an electronic system for the administration of medicament mixtures.
WO2004/011071 discloses a system for administering medicaments, wherein the two medicament containers are of different kinds.
WO2004/011067 and 011070 also disclose systems for administering medicament mixtures, wherein 01170 claims the administration of a plurality of co-formulated medicaments with a medicament which is not suitable for co-formulation.
WO2004/011067 claims a simple system for administering medicaments which are stored in separate containers but which can be administered to the patient in the form of a mixture.